This invention relates to vacuum cleaners and, more particularly, to an arrangement for reducing the noise generated by the exhaust air flow of the vacuum cleaner.
In a vacuum cleaner, there are two primary sources of noise. The first primary source is noise due to mechanical vibration of the motor blower assembly and the second is noise generated by the exhaust air flow of the vacuum cleaner. It is a goal of the vacuum cleaner designer to reduce these noises to a minimum, in order to reduce as much as possible annoyance to an operator of the vacuum cleaner. An arrangement for reducing noise produced by mechanical vibration of the motor blower assembly is disclosed in U.S. Pat. No. 4,864,683, assigned to the assignee of the present invention, the contents of which are hereby incorporated by reference herein. In the drawings of the referenced patent, although not described nor claimed, there is shown a labyrinthine arrangement of walls formed as part of the housing which function to baffle the exhaust air flow so as to reduce the noise generated thereby. However, this particular arrangement has proven to be difficult to implement, due to molding constraints.
It is therefore a primary object of the present invention to provide a practical arrangement for reducing the noise generated by the exhaust air flow in a vacuum cleaner.
When designing a line of vacuum cleaners with different models having different features and selling for different prices, it is desirable for the sake of economy to have as much commonality of parts as possible among the various models. A desirable feature of a higher priced model is that it is quieter in operation than a lower priced model. Accordingly, it is a further object of this invention to provide a noise reducing arrangement as described above which may be selectively incorporated in different models while still retaining maximum commonality of parts.